(262ax) Diffusiophoresis of a pH-Regulated Toroidal Polyelectrolyte in a Solution Containing Multiple Ionic Species

Considering recent application of diffusiophoresis in biosensing technology, we extend previous analysis for the diffusiophoresis of a toroidal PE at a fixed charge density to that at a pH-regulated condition in the presence of multiple ionic species so that the underlying assumptions are more realistic. The diffusiophoretic behaviors of the toroidal PE considered under various conditions are examined by varying its functional group density, size, and softness, and the solution pH and bulk salt concentration. The results of numerical simulation reveal that due to the competition between the hydrodynamic force and the electric force acting on a particle, the behavior of a toroidal PE can be different both quantitatively and qualitatively from the corresponding spherical PE. This implies that using an equivalent sphere to simulate the actual entity can yield significant deviation and, therefore, knowing the exact shape of an entity is necessary both in interpreting experimental data and in designing relevant devices.